Left-wing government candidate Claudia Sheinbaum is poised to become Mexico’s first female president, in an historic election overshadowed by violence, according to preliminary results. Frontrunner Sheinbaum, a former mayor of Mexico City, garnered between 58.3 and 60.7% of the votes, well ahead of her main challenger Xóchitl Gálvez, the electoral authority of the world’s most populous Spanish-speaking country said on Sunday evening. Gálvez came in second with 26.6 to 28.6%, the authority said after ballots from some 5,600 polling stations had been counted. The announcement of preliminary resu…